So to clarify - originally the plan was to launch an orbiter, lander (Russian built) and a small rover on the same Indian rocket. Now the Moon surface part is delayed to at least 2017-8 (will it switch to a Russian rocket) and the orbiter now is still planned in 2015-6. Is that correct? Would the payloads (http://www.russianspaceweb.com/luna_resurs.html) be changed (even added to both spacecrafts)?

I don't think the Russian lander was ever supposed to be launched on an Indian rocket.

Check out the article by Anatoly Zak at the link I gave. There's another all-Russian lander and orbiter mission before it (Luna-Glob, now also split up into two missions), perhaps you have confused with it (earlier reports were rather confusing).

I may be totally off-base here, but I have received the impression from Mr Zaks' site and some presentations made by Russian sources recently that the Indian rover is no longer part of Luna-Resurs at all.

I may be totally off-base here, but I have received the impression from Mr Zaks' site and some presentations made by Russian sources recently that the Indian rover is no longer part of Luna-Resurs at all.

- The project "Luna-Resurs" was planned to implement jointly with India. Has anything changed recently?

- We sent several requests to the Indian side that we have to change the concept of the lunar program, but the response from them has not yet been received. When they have some kind of response to our proposals, then our cooperation will continue.

So the ball is in the Indian's hands, and from the conflicting Indian news reports it looks like that they have yet to decide whether or not to leave the mission and do the whole landing mission by their own (I think the orbiter part has already been separated from the Russian side).

Completed sub-system level PDRs for Chandrayaan-2 and the rover proto model is under realization. Six wheel rover configuration is being worked out. The Indigenous lander development proposal is finalized;

Bleh, I think antriksh meant that the rover design is still being worked out.

The proposed Chandrayaan-2 mission has gone through all sorts of changes and twists and turns since it was first conceived. Originally, it was going to be landed on a Russian lander, but now it looks like ISRO will have to make the lander too. Oh well, should be a good learning exercise.

I really wonder why all rovers have 6 wheels, though. It's always seemed like overkill to me, since they never get pushed to their limits. I feel like it should always just be 4 wheels, but with extra motors for redundancy.

Bleh, I think antriksh meant that the rover design is still being worked out.

The proposed Chandrayaan-2 mission has gone through all sorts of changes and twists and turns since it was first conceived. Originally, it was going to be landed on a Russian lander, but now it looks like ISRO will have to make the lander too. Oh well, should be a good learning exercise.

I really wonder why all rovers have 6 wheels, though. It's always seemed like overkill to me, since they never get pushed to their limits. I feel like it should always just be 4 wheels, but with extra motors for redundancy.

ISRO had chosen two wheel rover, but now they have included 2 extra wheels. Initial rover design

Bleh, I think antriksh meant that the rover design is still being worked out.

The proposed Chandrayaan-2 mission has gone through all sorts of changes and twists and turns since it was first conceived. Originally, it was going to be landed on a Russian lander, but now it looks like ISRO will have to make the lander too. Oh well, should be a good learning exercise.

I really wonder why all rovers have 6 wheels, though. It's always seemed like overkill to me, since they never get pushed to their limits. I feel like it should always just be 4 wheels, but with extra motors for redundancy.

Thanks. Yeah, 4 wheels would seem easier and better for a few reasons, no?

Note that in the rover slide post by antriksh the mention of the LIBS (Laser Induced Breakdown Spectroscope). So basically that's supposed to be an Indian-made version of the LIBS system used on Curiosity.

Back when Chandrayaan-2 mission was first being proposed, I went and spammed email boxes and web forums with posts about the Curiosity ChemCam, including some Youtube vids posted here on NSF. Clearly the same advantages provided by this instrumentation on a Mars rover would also benefit a lunar rover. If anything, the even stronger lunar vacuum would further reduce laser attenuation and improve range as compared to Mars.

Note that in the rover slide post by antriksh the mention of the LIBS (Laser Induced Breakdown Spectroscope). So basically that's supposed to be an Indian-made version of the LIBS system used on Curiosity.

Back when Chandrayaan-2 mission was first being proposed, I went and spammed email boxes and web forums with posts about the Curiosity ChemCam, including some Youtube vids posted here on NSF. Clearly the same advantages provided by this instrumentation on a Mars rover would also benefit a lunar rover. If anything, the even stronger lunar vacuum would further reduce laser attenuation and improve range as compared to Mars.

Also, Sanman, I found this MS thesis which digs around the question of number of wheels. Page 29. http://c3p0.ou.edu/IRL/Theses/Roman-MS.pdfBut here's my question: if the benefit is simpler design, why not three wheels? 4 wheels seem intuitively more stable because we think in terms of boxes. But, given the same ortho-centre vertex distance, and CG height off the ground - how about a tetrahedral rover? Solar panels on all slanted surfaces that don't accumulate as much dust, reduced surface area/volume contributing to better thermal management... In any case I think the wheel walking mode offered by the rocker bogie suspension, and the reduction of surface pressure wins 6-wheelers the contest.[1]

I know LIBS at locally reduced pressures is also more sensitive, allowing faster, and greater expansion of the plasma - hastening the transition from a continuous thermal spectrum to an atomic one, and increasing spatial resolution. But won't global lack of pressure, i.e. no retarding force of an atmosphere, allow this plasma to continue expanding for a much longer time? That'd mean you need a larger aperture, and a longer delay between continuum and elemental emission, or worse: a confounding overlap. The lack of "contaminant" species in the atmosphere which are also emitting, may improve S/N, but I think it'll still be challenging doing it on the moon.[1]

[1] In other words, lots of trade-offs - for all things

As an aside, what e-mail inboxes did you spam? I'll join you the next time round.. I didn't know ISRO replies to e-mails lol